Molecular markers associated with seed weight in two soybean populations

Abstract

Seed weight (SW) is a component of soybean, Glycine max (L.) Merr., seed yield, as well as an important trait for food-type soybeans. Two soybean populations, 120 F4-derived lines of 'Young'xPI416937 (Pop1) and 111 F2-derived lines of PI97100x'Coker 237' (Pop2), were mapped with RFLP makers to identify quantitative trait loci (QTLs) conditioning SW across environments and populations. The genetic map of Pop1 consisted of 155 loci covering 973 cM, whereas Pop2 involved 153 loci and covered 1600 cM of map distance. For Pop1, the phenotypic data were collected from Plains, GA., Windblow, N.C., and Plymouth, N.C., in 1994. For Pop2, data were collected from Athens, GA., in 1994 and 1995, and Blackville, S.C., in 1995. Based on single-factor analysis of variance (ANOVA), seven and nine independent loci were associated with SW in Pop1 and Pop2, respectively. Together the loci explained 73% of the variability in SW in Pop1 and 74% in Pop2. Transgressive segregation occurred among the progeny in both populations. The marker loci associated with SW were highly consistent across environments and years. Two QTLs on linkage group (LG) F and K were located at similar genomic regions in both populations. The high consistency of QTLs across environments indicates that effective marker-assisted selection is feasible for soybean SW.

QTL analyses of seed weight during the development of soybean (Glycine max L. Merr.)

“…To date, QTL analysis of seed traits concentrated on unconditional QTL measured at the harvest stage (Mansur et al, 1996;Mian et al, 1996;Hyten et al, 2004). But no information (by early 2008) was available for QTL analysis of the behavior of seed weight gain over growing seasons in soybean.…”

“…Traditionally, plant improvement has relied on phenotypic selection of populations from crosses between cultivars and experimental lines (Stuber et al, 1992). Improvements in soybean seed weight by gene introgression has been slowed because phenotypic selection is complicated by significant genotype  environment interactions (GE) (Mansur et al, 1996;Mian et al, 1996). Consequently, selection for soybean cultivars with high and stable 100-seed weight requires evaluation in multiple environments over several years, which is expensive, time consuming and labor intensive.…”

“…Molecular markers offer a faster and more accurate approach to breeding for traits such as seed weight, as selection can be based on genotype rather than solely on phenotype (Mansur et al, 1996;Mian et al, 1996). The use of molecular markers for indirect selection of important agronomic traits, or marker-assisted selection (MAS) can improve the efficiency of traditional plant breeding (Allen, 1994).…”

“…In the past decade, several studies have focused on the mapping of quantitative trait loci (QTL) associated with soybean seed weight (Mansur et al, 1996;Mian, 1996;Hoeck et al, 2003;Zhang et al, 2004;Panthee et al, 2005). In most of these reports, the trait was only measured after harvest.…”

Identification of SSR markers associated with seed coat permeability and electrolyte leaching in soybean

“…Diers et al (1992) used the same interspecific soybean population to identify several molecular marker loci that were significantly associated with QTLs for seed protein and oil. Other workers utilized molecular markers to identify several genomic regions significantly associated with seed protein, oil, seed weight and sucrose content in different intraspecific soybean populations (Mansure et al, 1993;Lee et al, 1996;Mian et al, 1996;Maughan et al, 1996;Brummer et al, 1997). The objective of this study was to use SSR markers to identify quantitative trait loci associated with seed coat permeability and electrolyte leaching in an intraspecific F 2 soybean population.…”